Recording assay device

ABSTRACT

The invention herein described relates to an assessment device comprising an assay part and a detachable recording part. The assessment device facilitates the rapid assaying and processing of tissue/fluid samples by healthcare workers. Also, advantageously, the result of the assay is only apparent to the healthcare worker after interrogation of the recording part at a processing facility.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of application Ser. No.09/381,561, filed Sep. 17, 1999 now abandoned and entitled “RECORDINGASSAY DEVICE”, which, in turn, is a National Stage filing under 35U.S.C. §371, of PCT Application No. PCT/GB98/00815, filed on Mar. 18,1998, and in turn, claims priority under 35 U.S.C. §119 (a)-(d) fromGreat Britain Application Serial No. 9705667.5, filed Mar. 19, 1997.Priority as to all of the preceding applications recited above, ishereby claimed, and the entire disclosures of each of the saidapplications are incorporated herein by reference in their entireties.

The invention herein described is an assay and recording means for usein, particularly but not exclusively, the diagnosis and/or analysis oftissue and/or fluid samples taken from a human or animal which comprisesan assay part and a detachable data recording part.

The analysis of tissue or fluid samples is of crucial importance if theappropriate diagnosis of a patient is to be made by a healthcare worker.Also, there are numerous conditions that need constant monitoring tomaintain the correct treatment regime. For example, and not by way oflimitation, infectious disease (including HIV), diabetes, osteoporosis,tumour cell markers, reproductive endocrinology, thyroid diseasehaematology, therapeutic drugs, drugs of abuse, cardiac disease,treatment monitoring clinical trials assessment.

Also, it is apparent that the human genome project will identify genesthat are involved, either directly or indirectly, in a number ofinherited genetic diseases. Clearly it will be important to efficientlyprocess this genetic information to offer appropriate treatment and/orcounseling to individuals that are genetically predisposed to certaindiseases. It is highly likely that both conventional processingfacilities (i.e. to deal with monitoring various metabolites asdescribed above) and also new means to efficiently process geneticinformation will be required to deal with expanding healthcare.

It is also apparent that there are situations where adequate medicaladvice/treatment is either unavailable or not easily accessible toindividuals. For example, and not by way of limitation, armed forcespersonnel on active service in war zones, armed forces personnel onactive service in non-war situations but are effectively remote frommedical assistance (i.e. ships, submarines etc), individuals that farmin remote areas (i.e. Australian outback, Africa), individuals who workfor long periods away from adequate medical assistance (i.e. workers onoil/gas installations, research workers in polar or tropical regions,merchant navy personnel). It is important that these individuals receiverapid and reliable diagnosis of their condition so that the correcttreatment is administered.

Also a number of the planets inhabitants live on remote islands that donot have extensive medical support and may require a rapid means todiagnose a condition that obviates the need for the individual to visita mainland hospital or alternatively for a doctor to visit theindividual on the island to remove samples for analysis.

On a less extreme note there are examples where, although a hospital islocal to an individual, there may be extenuating circumstances thatprevent or make difficult the attendance of the individual at anoutpatients clinic to give samples for testing. Those suffering, forexample, from bronchitis or emphysema, the elderly and infirm and anyother individuals who would find a trip to their local hospitalphysically stressful and potentially hazardous. Currently, patients ofthis type can have home visits to monitor their condition. However,these are expensive and time consuming since some of a healthcareworkers effective time is spent travelling to the patients home.

In addition it may be desirable to analyse the recorded result of anassay by a healthcare worker at a data processing site remote from thepatient rather that rely on the patient to record and report the resultof the test. There are certain patients, (i.e. those suffering frommental disorders e.g. depression schizophrenia), where it may bedesirable to keep the results of an assay secret until the healthcareworker can process the data to enable the correct diagnosis to bedetermined. It is well known in the art that patients can willfullyinterfere with an assay to give an erroneous measure of the particularvariable monitored by the assay. If the recording device merely recordsthe information for subsequent processing and analysis this possibilityis minimised.

This has particular relevance in clinical trial assessment of candidatedrugs to provide a non-biased data collection means from treated andplacebo groups to ensure a reliable assessment of drug efficacy isobtained.

It is therefore an object of the invention to provide a generic assayand a recording device which efficiently monitors an individuals healthstatus.

It is a further object of the invention to provide an assay andrecording means wherein said recording means is detachable from saidassay means.

According to a first aspect of the invention there is provided anassessment device comprising an assay part and a recording part whereinsaid recording part is detachable from said assay part.

In a preferred embodiment of the invention said assessment device isselectively sized and shaped to facilitate handling and transport of theassessment device to the relevant processing facility.

In a preferred embodiment of the invention said recording device isselectively sized and shaped to facilitate handling and transport of therecording device to the relevant processing facility.

The above embodiment relates to a recording device that is sufficientlysmall and light to be transported via a conventional transport means forexample, and not by way of limitation, the postal service or courierservice.

In an alternative preferred embodiment of the invention said recordingdevice may be adapted to facilitate data transfer via electronic means.

It will be apparent that in subsequent years the use of the Internetwill become more widely accessible to the general public. The recordingdevice may therefore be adapted to interface with a personal computerwithin an individuals home or place of work. Data transfer ideally willbe encrypted to prevent third party access and decoded at a processingfacility via responsible healthcare worker.

In yet a further preferred embodiment of the invention said detachablerecording device is provided in retro-fit form, i.e. it may be desirableto adapt a pre-existing assay device to receive a recording part toenable data recording and storage.

It will be apparent from the above embodiment that the assessment devicemay be manufactured as a single unit. Alternatively, via suitableadaptation, said recording part or device may be attached to an existingassay part or device to enable data recording.

In yet a further preferred embodiment said recording device is a microprocessor or other similar electronic device. Alternatively, saidrecording device is photographic, comprising, for example, aphotographic emulsion, the stored images of which are developed at aprocessing facility.

It will be apparent that the above means for recording data from theassay can be processed by conventional means at the processing facilityby down loading the stored information/images at a computer by ahealthcare worker. Alternatively, if the worker has access to theinternet the data/images can be transferred electronically from theindividual to the healthcare worker at the processing facility.

In yet a further preferred embodiment of the invention there is providedan assessment device comprising an assay part with at least one sampleapplication well.

Reference herein to sample application well is intended to encompass anyreceptacle, recess, indentation, or well into which a tissue/fluidsample can be placed.

Reference herein to a fluid sample is intended to include both a liquidand a gas sample, for example, urine, blood, saliva, mucous, pus, semen,breathe.

In a preferred embodiment of the invention said recording assay deviceis characterised by multiple sample application wells. Ideally, one ormore of said well or wells is provided, suitably impregnated, withmaterials for sampling said fluid sample.

In yet a further preferred embodiment of the invention said assay partis adapted by the provision of at least one primary conduit in fluidconnection with said sample application well. Ideally said primaryconduit contains assay reagents in some instances suitable for dilutingsaid sample fluid. More preferably further still, said conduit issuitably sized to facilitate capillary flow of said sample fluidtherethrough.

In yet a further preferred embodiment of the invention said assay partis further adapted by the provision of at least one secondary conduitwhich is in fluid connection with one or more of said sample applicationwells; and which is ideally also adapted to provide for capillary flowtherethrough. Preferably further still said secondary conduit containsassay reagents, ideally of a nature different to the assay reagents insaid primary conduit but most suitably compatable therewith so as toprovide, in total, for the complete and selected assaying of said fluidsample as it flows through either or both of said primary/secondaryconduits.

In yet a further preferred embodiment of the invention at least onecontrol or calibration is provided in the assessing device. For example,a control conduit may be provided for monitoring flow through thedevice. Said control conduit may optionally be provided with assayreagents, or alternatively, the elements, to be detected by the assay inorder to produce a positive result or identification.

In yet still a further preferred embodiment of the invention there isprovided an assay part provided with at least one assay conduit which isfurther characterised by a detection zone to facilitate the detection ofthe product(s) of the assay.

According to yet a further aspect of the invention there is provided amethod to assay and record a tissue/fluid sample from an individualcomprising;

-   (i) applying a sample to a sample application well of an assessment    device as hereindescribed;-   (ii) mixing said sample with at least primary assay reagents; and-   (iii) recording the data from i-ii via the recording part.

It will be apparent to one skilled in the art that this method enablesthe rapid processing of an applied fluid/tissue sample within minutes ofapplication to the sample well. This will reduce erroneous assay ofsamples due to sample degradation during long term storage.

It is well known in the art that assay reagents comprise, and not by wayof limitation, buffers, substrates, enzymes, antibodies, co-factors,intermediary metabolites, nucleic acid. It will also be apparent thatthere are well known in the art means to assay various factors. Forexample, antibody techniques using polyclonal/monoclonal antibodies tospecific epitopes (e.g. drugs, hormones, steroids, tumour specific cellsurface antigens, viral/bacterial antigens). Enzyme based techniques formonitoring, for example, glucose or cholesterol in blood plasma. Many ofthese techniques rely on a colour change as an indication of thepresence of the desired agent(s). More recently chemiluminescent and/orfluorescent detection means are available and will be applicable to theassay recording device.

According to yet a further aspect of the invention there is provided akit comprising; an assessment device as hereindescribed, assay reagentsand optionally protective packaging for transport of the recordingdevice to the processing facility.

It will be apparent that the recording assay device has widespreadapplication in the diagnosis of disease. It may also have a role inclinical trials assessment of potential therapeutic agents providing anon-biased means of collecting data from treated and placebo groups toensure a reliable assessment of drug efficacy is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described, by example only,and with reference to the following figures wherein,

FIG. 1 is a diagrammatic representation of the assay part of anassessment device;

FIG. 2 is a diagrammatic representation of the internal layout of anassessment device; and

FIG. 3 represents a diagrammatic representation of an external view ofan assessment device

DESCRIPTION

Referring to FIG. 1, a diagrammatic representation of an assay part ofthe recording assay device is shown. The assay part is characterised bythe presence of a selectively sized and shaped sample application well(1) which is circular in the diagram. The sample application well (1) isin fluid contact with a primary assay reagent conduit (2). The primaryreagent conduit is selectively sized to facilitate the movement ofsample applied to the application well (1) by capillary flow. Theprimary reagent conduit contains at least some of the reagents necessaryto complete a reaction with the sample applied to the sample well (1) orbegin an initial reaction with the applied sample. Additionally thereagents may represent solutions used to dilute the sample and/orprimary assay reagents. A single assay well (1) is shown in the diagram.However, the device may be adapted to contain multiple application wellsin fluid contact with one or more primary reagent conduits.

The primary assay reagent conduit comprises filter paper, or othersuitable means, impregnated with the primary assay reagents and cancomprise additionally, or alternatively, any of the followingalternatives;

-   (i) multiple channels formed in paper or other water permeable    material by impregnation with polymers to form water impermeable    regions;-   (ii) multiple channels formed in nitrocellulose or other water    permeable diagnostic or filter membrane by impregnation with wax to    form water impermeable regions;-   (iii) formation of strips of water permeable material within a sheet    of the material by cutting regions from a sheet of the material, in    order to form multiple channels;-   (iv) printing (e.g. by silk screen) of a water permeable material    (e.g. nitrocellulose or other material used to make diagnostic and    filter membranes) in emulsion or other fluid form onto a water    impermeable surface to create channels of the water permeable    material;-   (v) multiple water permeable channels comprised of any material and    produced by any method;-   (vi) a single water permeable channel or strip comprised of any    material and produced by any method. In a single channel device    there would be one or more detection zones;-   (vii) a channel(s) of free space, within a water impermeable    structure, forming a capillary in which liquid may flow by capillary    action. This technique is sometimes referred to as a “capillary    flow” diagnostic device. In a single channel device there would be    one or more detection zones; and-   (viii) other types of channel.

In use a fresh sample applied at (1) is moved via capillary action intothe primary reagent conduit. The filter paper may be hydrophilic over atleast part of its area to restrict and/or concentrate the flow of samplealong the primary conduit (2).

The primary reagent conduit is optionally in fluid contact with asecondary reagent conduit (3) containing secondary assay reagents. Thesecondary reagent conduit is selectively sized to facilitate capillaryflow of sample from the primary reagent conduit. FIG. 1 represents asingle secondary reagent conduit. In an alternative embodiment of theinvention more than one secondary reagent conduit may be presentcontaining reagents required to complete the assay. Again capillary flowwill draw the sample/primary assay reagent mix into the secondary assayconduit (3) to facilitate the reaction of secondary reagents with thesample/primary assay reagent mix. A detection zone (4) is selectivelypositioned to interact with the reaction mixture once all componentshave been mixed and the assay completed. The detection zone (4) maycontain substrates necessary to allow detection of the product of theassay. Alternatively, these substrates may be incorporated in theprimary and/or secondary mix. Detection may be via a colour change orother suitable means (e.g. chemiluminescence, fluorescence emission).

Two preferred detection means are readily applicable to the assessmentdevice;

-   -   (i) recording of an electrochemical reaction by a microprocessor        or other solid-state device. Amperometric and potentiometric        assay detection techniques are appropriate. This is the        preferred detection system, as the removable recording system        can be kept from contacting physically with any of the        components of the sample by means of the electrical connection        between the detection zone and the recording device, thus        rendering it completely safe from infectious risk on handling,        FIGS. 2 and 3; and    -   (ii) recording of a photometric reaction by a photographic or        other light sensitive film or device. Chemiluminescence and        fluorescence are appropriate. The film and detection zone can be        separated by a clear water impermeable layer which will prevent        the film from contacting physically with any of the components        of the sample.

Additionally other detection means include;

-   (iii) reflectance or transmittance photometry; production of a    stable dye on a surface by biochemical or chemical reaction,    including ELISA;-   (iv) microparticles, including polymers, metallic and non-metallic    elements and other materials;-   (v) soluble coloured substances, including dyes. These would be    determined by a light reflectance technique (including fluorimetry)    or light transmittance technique or another technique related to any    specific feature of any soluble substance used; and-   (vi) other assay detection systems.

The detection is recorded and stored in a microprocessor located in therecording means, not shown in FIG. 1. The assay part is further adaptedby the provision of a waste well (5) to store excess sample/reactionmix.

Referring to FIG. 2, an alternative embodiment of an assay part is showndiagrammatically with a detachable recording part (10) along anindicated separation line (14). The single sample application well (1)is shown in fluid connection with a plurality of conduits (6). Theconduits identified in FIG. 2 may contain alternate assay reagents tofacilitate multiple testing of variables of the applied sample. Forinstance, glucose, salts, hormone levels, the detection of specificepitopes via immune reaction. The plurality of conduits (6) each containa detection zone (4), each of which is connected to a microprocessor (8)via electrical connections (7) to facilitate interrogation of the assayin the detection zone (4). The recording assay device is also providedwith a test ready indicator (9) to monitor device status therebyallowing the user to readily identify when the device has completed theassay.

Referring to FIG. 3 an external diagrammatic representation of arecording assay device is shown. The outer casing (12) is manufacturedfrom a durable material, (e.g. reinforced plastic). The recording part(10) is easily detached from the assay part along a perforated strip(11) in registration with the separation line (see FIG. 2).Alternatively the assay part and recording part may be selectivelyattached via a clip, hasp, lock, or any suitable-means to facilitate theattachment or detachment of said assay part from said recording part. Inuse the patient applies a sample to a sample well (1) through anapplication port (13). When sufficient time has lapsed to allow theassay to reach an end point the test ready indicator (9) conveys this tothe user. The user can then simply detach the recording part from theassay part and send the data to a processing facility for decoding andinterrogation.

The invention therefore provides for a device that operates in a stable,reliable and reproducible manner and advantageously the results of theassay are not available to a user until further, remote, processing hasoccurred.

1. An assessment device, comprising: a substrate having an indicated separation line defining first and second portions; an assay element, arranged on the first portion; a data recording element, arranged on the second portion; and means for communicating data from the assay element to the recording element, the data communication means arranged onto the substrate.
 2. The assessment device of claim 1, further comprising: an outer casing comprising a perforated strip in registration with the separation line.
 3. The assessment device of claim 1, wherein: the assay element comprises: a sample application well; and a detection zone in fluid communication with the sample well; and material for assaying a fluid sample, contained in the assay element.
 4. The assessment device of claim 3, wherein: the detection zone comprises means for detecting an assay product.
 5. The assessment device of claim 1, wherein: the means for communicating data from the assay element to the recording element comprises an electrical connection.
 6. The assessment device according to claim 1, wherein: the recording element comprises means for electronic downloading and transfer of data to a processing facility.
 7. The assessment device according to claim 1, wherein: the recording element comprises an electronic storage device.
 8. The assessment device according to claim 1, wherein: the recording element comprises a microchip or microprocessor.
 9. The assessment device according to claim 1, further comprising: an indicator actuated on completion of the assay.
 10. The assessment device according to claim 1, wherein: the assay element comprises a further sample application well, the further sample application well containing a material for assaying a fluid sample.
 11. The assessment device according to claim 1, wherein: the assay element comprises a sample application well, the well comprising a surface impregnated with a material for assaying a fluid sample.
 12. An assessment device, comprising: a substrate having an indicated separation line between first and second portions; an assay element, arranged on the first portion, comprising: a sample application well; a detection zone in fluid communication with the application well; and material for assaying a fluid sample, contained in the assay element; a data recording element comprising an electronic storage device, arranged on the second portion; and an electrical connection between the assay element and the recording element for communicating data from the assay element to the recording element, the electrical connection irreversibly broken when the first and second portions are separated.
 13. The assessment device according to claim 12, further comprising: an indicator actuated on completion of an assay.
 14. The assessment device according to claim 12, wherein: the recording element is provided with data communication control means for electronic downloading and transfer of data to a processing facility.
 15. An assessment kit, comprising: the assessment device according to claim 12; and protective packaging for transport of the recording element to a processing facility.
 16. The assessment device according to claim 12, further comprising an outer casing comprising a perforated strip in registration with the separation line.
 17. An assessment device, comprising: a substrate having first and second portions; an assay element, arranged on the first portion; a data recording element, arranged on the second portion; means for communicating data from the assay element to the recording element, the data communication means arranged onto the substrate; and a casing having an indicator line defining first and second elements of the casing, such that separating the elements along the indicator line detaches the first and second portions.
 18. The assessment device of claim 17, wherein: separating the elements along the indicator line severs the means for communicating data from the assay element to the recording element. 